package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {

    }

    @Override
    public List<CategoryEntity> listWithTree() {

        // 1、查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);
        // System.out.println(entities);

        // 获取父分类
        /**
         List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
         categoryEntity.getParentCid() == 0
         ).collect(Collectors.toList());
         */

        // 过滤出父分类，然后父分类再通过map获取子分类
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
                categoryEntity.getParentCid() == 0
        ).map((menu) -> {menu.setChildren(getChildrens(menu, entities));
            return menu;
        }).collect(Collectors.toList());

        // System.out.println(level1Menus);

        // 2、组装成父子的树形结构
        return level1Menus;
    }


    /**
     * 递归查找所有菜单的子菜单
     *
     * @param root
     * @param all
     * @return
     */
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all) {
        List<CategoryEntity> children =  all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEngity ->{
            // 1、找到子菜单
            categoryEngity.setChildren(getChildrens(categoryEngity, all));
            return categoryEngity;
        }).sorted((menu1, menu2) ->{
            // 2、菜单的排序
            return (menu1.getSort() == null ? 0 : menu1.getSort())- (menu2.getSort() == null ? 0 : menu2.getSort());
        }).collect(Collectors.toList());

        return children;
    }

}